A daily dose of the antioxidant selenium doesn't appear to elevate "bad" cholesterol levels, and may in fact prompt a very modest boost in "good" cholesterol, a new British study reveals. The finding comes from a six-month examination of the impact of various dosages of the supplement on the cholesterol levels of healthy people in England. "The issue is that there have been an awful lot of studies, about eight, that have looked at blood cholesterol, both good and bad, and have found an association with high blood selenium," said study author Margaret P. Rayman, a professor of nutritional medicine at the University of Surrey in Guildford, England. But an association is only that; it doesn't mean one thing causes another.